| 摘要 |
PURPOSE:To secure smooth movement of a valve being opened by forming a damper chamber in a piston which drives a valve by means of hydraulic pressure, introducing oil into said damper chamber through a check valve when opening the valve, and enabling a damping operation to take place only when closing the valve. CONSTITUTION:A damper chamber 2 is formed in a piston 1 which drives a valve 8, and a damping element 1 is projected into this chamber. A passage 4 and a check valve 5 are provided in the damping element 1 and, when opening a valve, the oil being introduced into a cylinder 3 is also introduced into the damper chamber 2 through the passage 4 and the check valve 5, causing smooth valve opening movement to take place. When closing the valve, the check valve 5 closes the passage 4, causing the damper chamber 2 to produce a damping effect. |
